Factorial

# title: Factorial
# source: https://rosettacode.org/wiki/Factorial
# category: Rosetta Code
# difficulty: Intro
# summary: Compute factorial values both recursively and iteratively, well past the 64-bit range.
# tags: popular, math, recursion, loops, bignum
# vibe: 0.4

def recursive_factorial(n)
  if n <= 1
    1
  else
    n * recursive_factorial(n - 1)
  end
end

def iterative_factorial(n)
  result = 1
  value = 2
  while value <= n
    result = result * value
    value = value + 1
  end
  result
end

def run
  {
    recursive_10: recursive_factorial(10),
    recursive_25: recursive_factorial(25),
    iterative_50: iterative_factorial(50)
  }
end